chore(deps): align rusqlite 0.40 + git2 0.21 with OpenHuman host (#59)

rusqlite and git2 are native `links = "…"` crates (libsqlite3-sys ->
links=sqlite3, libgit2-sys -> links=git2). OpenHuman pins rusqlite =0.40.0
(bundled) and git2 0.21 (vendored-libgit2); the crate pinned rusqlite 0.32 /
git2 0.19. Two versions of a links crate in one binary is a hard Cargo error,
so the host could not activate its `tinycortex` dependency.

Bump both to the host versions and adapt the API deltas:

- rusqlite >= 0.33 dropped FromSql for usize: VectorStore::count reads COUNT(*)
  as i64 and converts via usize::try_from (matches the host's own fix).
- git2 0.21: Tag::message() -> Result<Option<&str>>; StringArray::Iter::Item ->
  Result<Option<&str>>; Buf::as_str() -> Result<&str, Utf8Error>. Adapt the
  checkpoint tag reader, the two tag-name loops, and patch_text.

cargo check --all-targets clean; diff/ledger + checkpoint tests (38) pass.

Author: senamakel

Cargo.toml

@@ -21,11 +21,15 @@ exclude = [
 anyhow = "1"
 async-trait = "0.1"
 chrono = { version = "0.4", features = ["serde"] }
-git2 = "0.19"
+# Native-linking deps pinned to OpenHuman's versions so the host and the crate
+# link ONE bundled SQLite and ONE libgit2 (both are `links = "…"` crates; two
+# versions in one binary is a hard Cargo error). Keep in lockstep with the host
+# root Cargo.toml when either side bumps.
+git2 = { version = "0.21", default-features = false, features = ["vendored-libgit2"] }
 parking_lot = "0.12"
 rand = "0.8"
 regex = "1"
-rusqlite = { version = "0.32", features = ["bundled"] }
+rusqlite = { version = "0.40", features = ["bundled"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 sha2 = "0.10"

src/memory/diff/ledger.rs

@@ -366,7 +366,9 @@ impl Ledger {
         };
         Ok(Some(checkpoint_from_message(
             checkpoint_id,
-            tag.message().unwrap_or(""),
+            // git2 0.21: Tag::message() is Result<Option<&str>, _>; a non-UTF8
+            // or missing message degrades to an empty checkpoint body.
+            tag.message().ok().flatten().unwrap_or(""),
         )))
     }
 
@@ -375,8 +377,9 @@ impl Ledger {
         let pattern = format!("{CHECKPOINT_PREFIX}*");
         let names = self.repo.tag_names(Some(&pattern))?;
         let mut out = Vec::new();
-        // StringArray::iter() yields Option<&str>; drop non-utf8 names.
-        for name in names.iter().flatten() {
+        // git2 0.21: StringArray::iter() yields Result<Option<&str>, _>; keep
+        // only successfully-decoded utf8 names.
+        for name in names.iter().filter_map(|r| r.ok().flatten()) {
             if let Some(ckpt) = self.get_checkpoint(name)? {
                 out.push(ckpt);
             }
@@ -394,7 +397,8 @@ impl Ledger {
         let pattern = format!("{CHECKPOINT_PREFIX}*");
         let names = self.repo.tag_names(Some(&pattern))?;
         let mut deleted = 0u64;
-        for name in names.iter().flatten() {
+        // git2 0.21: StringArray::iter() yields Result<Option<&str>, _>.
+        for name in names.iter().filter_map(|r| r.ok().flatten()) {
             if let Some(ckpt) = self.get_checkpoint(name)? {
                 if ckpt.created_at_ms < older_than_ms {
                     self.repo.tag_delete(name)?;
@@ -545,7 +549,8 @@ fn oid_hash(oid: Oid) -> Option<String> {
 fn patch_text(diff: &git2::Diff, delta_idx: usize) -> Option<String> {
     let mut patch = git2::Patch::from_diff(diff, delta_idx).ok().flatten()?;
     let buf = patch.to_buf().ok()?;
-    let text = buf.as_str()?;
+    // git2 0.21: Buf::as_str() returns Result<&str, Utf8Error>.
+    let text = buf.as_str().ok()?;
     if text.trim().is_empty() {
         None
     } else {

src/memory/store/vectors/store.rs

@@ -22,6 +22,7 @@
 use std::path::Path;
 use std::sync::Arc;
 
+use anyhow::Context;
 use parking_lot::Mutex;
 use rusqlite::Connection;
 
@@ -369,15 +370,18 @@ impl VectorStore {
     /// Returns the number of entries in a namespace (or all if `None`).
     pub fn count(&self, namespace: Option<&str>) -> anyhow::Result<usize> {
         let conn = self.conn.lock();
-        let count: usize = match namespace {
+        // SQLite COUNT(*) is an i64; rusqlite (>= 0.33) no longer implements
+        // FromSql for usize, so read as i64 and convert. Overflow is impossible
+        // in practice but handled rather than silently truncated.
+        let count: i64 = match namespace {
             Some(ns) => conn.query_row(
                 "SELECT COUNT(*) FROM vectors WHERE namespace = ?1",
                 rusqlite::params![ns],
                 |row| row.get(0),
             )?,
             None => conn.query_row("SELECT COUNT(*) FROM vectors", [], |row| row.get(0))?,
         };
-        Ok(count)
+        usize::try_from(count).context("vector count did not fit in usize")
     }
 
     /// Lists all distinct namespaces.